Washington: Infant formula causes cellular death that may contribute to necrotizing enterocolitis, a severe intestinal condition that is often fatal and occurs most commonly in premature infants, says a new study. University of California San Diego bio-engineers, based their study on tests comparing the digestion of fresh human breast milk and nine different infant formulas. Scientists have long known that premature infants fed formula are more likely to develop necrotizing enterocolitis than those fed breast milk.
The condition is the leading cause of death from gastrointestinal diseases in premature infants, but the underlying mechanism has not been understood, the journal Paediatric Research reported. Alexander Penn, working in the Microcirculation Lab of Geert Schmid-Schonbein, bio-engineering professor from the UC San Diego Jacobs School of Engineering, believes they have come closer to an answer, according to a California statement.
The intestines of healthy adults and older children have a mature mucosal barrier that may prevent damage due to free fatty acids. However, the intestine is leakier at birth, particularly for pre-term infants, which could be why they are more susceptible to necrotizing enterocolitis. Therefore, the researchers wanted to know what happens to breast milk as compared to infant formula when they are exposed to digestive enzymes.
Overwhelmingly, the digestion of formula led to cellular death, or cytotoxicity - in less than five minutes in some cases - while breast milk did not. For example, digestion of formula caused death in 47 percent to 99 percent of neutrophils while only six percent of them died as a result of milk digestion. The study found that breast milk appears to have a built-in mechanism to prevent cytotoxicity.
The research team believes most food, like formula, releases high levels of free fatty acids during digestion, but that breast milk is digested in a slower, more controlled, process. Currently, many neonatal intensive care units are moving towards formula-free environments, but breastfeeding a premature infant can be challenging or physically impossible and supplies of donor breast milk are limited.